1. Field of Invention
This invention relates to apparatus for cooling a cylindrical member in linear motion whereby the member is cooled homogeneously.
By a cylindrical member in linear motion is meant a product of elongated shape, for example a bar or a tube, which is moving along its longitudinal axis.
Apparatus according to the invention is particularly intended for cooling a steel product from the rolling temperature at the outlet from a rolling mill. It can nevertheless also be used for cooling after any forming or heat treatment operation.
2. Description of Prior Art
Apparatus for cooling a cylindrical steel member in linear motion delivered from a rolling mill, which apparatus uses in particular rings of nozzles or circumferential slots to distribute a cooling agent over the surface of the member, has been known for a long time. The cooling provided by such means is in general not sufficiently fast and homogeneous over both the perimeter of the cylindrical member in linear motion and its length, particularly where this cooling governs certain final properties of the member. The properties in question are linked with the production of an appropriate structure, for example a hardened and self-annealed surface layer, or again a fine grain ferritic structure, in the case of steel.